The Foot Posture Index is a tool that was originally developed by Tony Redmond to put a number on the posture or alignment of the foot. The Foot posture index is a composite number based on six observations of the foot:
For each observation a score is given from 2 (pronated or flat) to 0 (“normal”) to -2 (supinated or high arched. The score for each observation are added to given a composite score. The most flat or overpronated foot would score a 12 and the most supinated high arched foot would score a -12.